Electric-arc lamp



- (Ho Model.) 3 Sheets-Sheet 1.

N. H. EDGERTON A ELECTRIC ARG LAMP.

No. 268,392. Patented Dec. 5, 17882.

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(No Model.) I 3 Sheets- Sheet 2. N. H. EDGERTON.

ELEGTRIG ARG LAMP.

No. 268,392. Patented Deoy5, 1882.

l-NVENTOR! N. H. EDGERTO N,

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(No Model.) 3 Sheets-Sheet 3.

N. H. EDGERTON.

ELECTRIC ARO LAMP.

No. 268,392. Patented Dec. 5, 1882..

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UNITED STATES PATENT OFFICE.

NATHAN H. EDGERTON, OFPHILADELPHIA, PENNSYLVANIA.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 268,392, dated December 5, 1882.

Application filed May 15, 1882.

To all whom it may concern:

Be it known that I. NATHAN H. EDGERTON, of Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented new and useful Improvements in Electric Lamps; and I do hereby declare that the following is a full .and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

This invention relates to that class of electric-arc lamps which are adapted to cause illuinination by the production of the electric arc; and it consists mainly in the combination, with a proper supporting-frame, of three inclined guiding-tubes, held at such angles as to cause the carbon contained therein to meet under the action of gravitation at a single point.

It further consists in certain specific details of construction, which, in connection with the foregoing, will be fully described hereinafter.

In the drawings, Figure 1 is a perspective view of my improved lamp; Fig. 2, an enlarged sectional view, showing the tubes for holding the positive carbons; Fig. 3, aplan view with the cover-plate partially broken away to show the interior construction; Fig. at, a detached view, partially in section, of the tube for holding the negative carbon and the parts attached thereto; Fig. 5, a partial side view illustrating the mechanism for withdrawing the negative carbon from contact with the positive carbons; Fig.6, a front view of the same; Fig. 7, a partial plan view, the negative carbon being shown in its normal position to establish the arc; and Figs. 8 and 9, views illustrating the construction of a shunt to shift the current when the light goes out.

To enable others skilled in the art to make my improved lamp and properly use the same, 1 will proceed to describe fully its construction and manner of operation.

A, Fig. 1, represents a cast-metal frame or ring suspended by chains or a or other suitable means from any proper point of support, which consists of an inclined upper portion, a, supporting the vertical ring a and an inclined lower portion, a, supporting in any proper manner the semi-spherical glass globe at, as shown.

a Figs. 2 and 3, represents a metal cover, by means of which the interior of the lamp is protected from the entrance of dust or lint, and the diffusion of the light in an upward direction is also prevented.

(N0 model.)

a represents a bindingpost located directly upon the ring a? of the lamp without insulation, and a the positive terminal wire leading into the same.

a, Figs. 1 and 4., represents a binding-post located upon the ring a but insulated therefrom, and a the negative terminal wire lead ing therefrom.

a Figs. 1 and 2, represents a mica plate interposed between the bottom of the globe and the point of combustion for the purpose of preventing the hot carbon from falling onto the globe and cracking the same.

B B, Fig. 3, represent the positive tubes for holding the carbons, and O the negative tube, these tubes being located about the frame at a distance of one hundred and twenty degr .es apart, and being held at such an angle as to cause the carbons contained therein to meet under the action of gravitation at a single central point, as shown. The positive tubes B B are connected to the frame A without insulation, the frame itself receiving the current from the wire a, which is directly attached to the frame by the binding-post a, as shown. The negative tube (1 is insulated from the frame, and the terminal wire (t leading from its helices, is also insulated, the same being held by the insulated binding-post a,as shown. When these carbon points actually touch each other, as shown in Fig. 3, no light of course is produced; but when the negative carbon is lifted out of contact with the positive carbons, as indicated in Fig. 7, by the action of a current of electricity, the electric arc is established, andthe light thus formed in the manner well understood.

The mechanism for lifting the negative carbon out of contact with the positive carbons will now be described.

D D represent helices located upon the tube for holding the negative carbon, each of which is provided with a soft-iron core, (I, Fig. 4., having at its upper end a rod, (1, extending outward beyond the frame of the lamp, as shown.

(Z Figs. 4, 5, and 6, represents a connectingbar, by means of which the lower ends of the cores are united together, as shown.

01 represents a plate hinged to the connecting-bar, as shown, which is provided with a round opening, the circumference of which slightly exceeds the circumference of the carbon, as shown.

E represents a spring surrounding the up per end of the rod d, and c a threaded end having a nut, e, as shown. By means of this construction the power of the spring to resist pressure may be increased or diminished at will.

When the parts are in what may be termed, for convenience, their normal position when at rest, as shown in Figs. 3 and 4.that is, when no light is being formed-the-carbon in the negative tubeis held from downward movement by the contact ofits point with the points of the positive carbons. When, however, a current enters the lamp and passes from the positive carbons through the negative carbon to the helices D D, the latter are caused to draw up the soft-iron cores in the manner well understood. By this upward movement of the cores the hinged plate 01 secured to the connecting-bar (Z is caused to clamp the carbon, as shown in Fig. 5, and lift the same out of contact with the points of the positive carbons, and establish the arc and form the light, as shown in Fig. 7.

The general operation is substantially as follows: The parts being in their normal position when at rest, as indicated in Figs. 1, 3, and 4, no light will be produced, as no current is passing through the lamp. All the carbons will then be held at the central point by their contact with each other. When, however, a current enters the lamp through the wire a the frame, and the tubes B B, the same will pass through the negative carbon and its tube to and through the helices to the wire at, extending away from the lamp. By the action of the current on the helices the point of the negative carbon is withdrawn, by the mechanism before described, from contact with the points of the positive carbons, and the are being thus established, the light is formed. The positive carbons, as the points wear away in combustion, are kept in proper contact by the action of gravitation. The negative carbon also is advanced at the proper time by the action of gravitation, the weakness of the current at this time permitting the cores to descend far enough to bring the hinged plate at right angles to the carbon, when the latter of course is free to slide within the tube. The exact adjustment of the carbon, it will be understood, may be determined by the amountof movement permitted the cores by the adjusting-spring D.

Some of the advantages of the described construction are as follows: By the employment of two positive carbons in connection with one negative, in the manner described, a uniform consumption of the carbons in combustion is effected. By the employment, also, of three carbons in the manner described a uniform feeding of the carbons is automaticallyobtained. Bytheemploymentofthecover the interior space of the lamp is protected from the entrance of objectionable and inflammable matter. By the employment of the globe the hot droppings of carbon are caught, and the light is isolated from combustible substances. By the employment of the mica plate, also, the

globe is protected from injury. The globe is so attached to the lamp as to be readily re moved when it is desired to clean the same. If desired, the carbonsmay be located in horizontal planes, and be actuated by springs instead of gravity.

In Figs. 8 and 9 is represented an auxiliary device or shunt to shift the current when the light goes out, which will now be described.

A represents the frame before described.

E represents a helix secured to the frame at any proper point, which receives a wire, 0, from the helices D D, and extends the same to the insulated negative binding'post c, (a in previous figurcs,) as shown.

F represents a lever centrally pivoted by means of a suitable conducting wire or strip to the binding-post c, as shown.

G represents a stick or block of graphite depending from the frame into close proximity with one end of the lever F, as shown.

The operation is substantially as follows: When the lamp is in action and the current is flowing normally the parts are in the position shown in Fig. 8, the current then passing from the helices D D through the helix E to the biuding-postc; but when the flow is interrupted in the arc and the light goes out the heavy end of the lever F, being no longer sustained by the helix, drops, as indicated in Fig. 9, and causes the opposite end to make contact with the graphite, the current then passing from the frame through the graphite and lever to the binding-post, as shown, thus preventing the extinguishing of other lights in the circuit.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In combination with a propersupportingframe, three inclined guiding-tubes converging to a central point, and positive and negative carbons contained in the tubes, having suitable electrical connections, as described.

2. An electric lamp, substantially as described, having a supporting-frame with three inclined guidingtubes containing positive and negative carbons, substantially as described, and mechanism, substantially as described, for separating the point of the negative carbon from the points of the positive carbon, as set forth.

3. In combination with the helices D D, having the cores (1 d and connecting-bar (1 the pivoted clamping-plate (1 adapted to inclose the carbon, as and for the purpose described.

4. Theelectro-magnet E,interposed between the helices D D and the negative terminal 0, with its lever F or equivalent device, and the graphite rod G, connecting with the positive side of the lamp, substantially as shown and described.

This specification signed and witnessed this 11th day of May, 1882.

NATHAN ll. EDGERTON.

Witnesses:

HENRY M. BOYD, JOHN P. GLONINGER. 

